What is it you don't like about the arrangement, I think it looks prtty fair so we must be missing something..?
If she's not yet at school who normally has her during the day? You said you work too..
What days are you actually working?
On the face of it what he's asking for seems fairly reasonable (going with the final offer that is - ie 9 days each including one full weekend each and splitting the middle and you get her for xmas eve & xmas day and NY eve and NY day...)
I see it as follows:
Fri 17 - Mon 20 - weekend 4 days with dad
Extra days Tue 21 - Wed 22 (which he's willing to compromise on - Are you working these days? Reasonable for you to have these if you not working) - so say these 2 days with you
Thur 23 - Sat 25 - 3 days with you including xmas & split weekend
Sun 26 - Thu 30 - 5 days with dad (splitting weekend)
Weekend Fri 31 - Mon 3rd - weekend with mum
Presuambly starting school on the 4th?
So the split i basically
4 days weekend - dad
5 days - mum
5 days - dad
4 days weekend - mum
As you both work it seems fair to me that you have half the holidays each (now she is starting school). If he wants to see her more in the week when she's at school then he can always adjust his hours and do school pick ups etc. And if you're working then it'll save you having to find child care if he'll have her the days you are working.
The first thing I would ask him is is there some specifica reason he's fixed in these dates? Does he have family/relatives coming or planning on going to see? Has he booked the panto or other special event? He might be being 'stubborn' because he's got specific plans.
At the end of the day you could make life really difficult and simply not make dd available and then he'd have to take you to court. I'm not suggesting you take that route though, it's probably not in your dd's best interest to do that.
If he takes you to court (now or in the future) and she's at school, he's most likely to get awarded half the school holidays. Which is basically what is on the table now anyhow.
No court case would have this sorted for this year, and highly unlikely he'd get it sorted for next unless you and he both agreed. So you both need to be reasonable and compromise here; easier said than done of course, particularly with an ex.
So I suggest you try and find out from him why he is insisting on these dates, and if there's nothing specific and you are both working some of the holidays, then he will have to compromise. Explain about your work/holiday situation and remind him of the dates that dd is starting school and ask him to be considerate here.
Course he probably thinks he's being reasonable, and with the second/'final' option he probably is being fairly reasonable. You end up with 9 days each that way. You both get a full weekend and you split the middle weekend.
So probably need to know why you're objecting (probably to do with when your working/off work ?) to see where the issues are.
Suggest you start sorting out half term and Easter pretty soon too as you'll be needing to work out childcare options if he's not going to have her for you then. Oh and non pupil days...
It's not easy dealing with your ex and having to find a compromise that suits everyone. But in reflection do you think that perhaps you're being a little sensitive here with everything else that's going on?